3-1-9 Capacitors Flashcards
Capacitors are devices that oppose a change of voltage.
True
Energy is stored in __?__ in a capacitor.
an electrostatic field
The time it takes to charge and discharge a capacitor is measured in __?__.
time constants
The basic unit of capacitance is the __?__.
farad
Voltage across a capacitor lags the current through the circuit by __?__.
90 degrees
Capacitors are constructed to allow current to flow through them.
False
Charging or discharging a capacitor takes __?__.
5 time constants
Which of the following is a job that can be performed by a capacitor?
Store an electrical charge
Provide voltage for timing circuits
Make a correction to power factor
(all 3)
Power factor correction is not one of the main functions of a capacitor. Power factor is corrected by the substation transformer.
False
The voltage rating of a capacitor is actually the rating of the __?__.
dielectric
When a capacitor charges and discharges during each time constant, the voltage will change by __?__ of the amount left to reach the fully charged state.
63.2%
When looking at the current charging a capacitor and the voltage across the capacitor, the current is at a maximum when the voltage is __?__.
at zero
The faster the frequency of a circuit, the faster a capacitor charges and discharges.
True
Customers with motors that have a low power factor are a desirable load for an electrical provider.
False
A transformer is an example of a(n) __?__ load which would cause low power factor.
inductive
